古建筑修复用熟石灰性能优化及机理研究

研究了矿渣、循环流化床锅炉燃烧脱硫灰(CFBC脱硫灰)和硅灰对熟石灰性能的影响及作用机理,并与理想的古建筑修复材料——强度等级为NHL2的天然水硬性石灰(简写为NHL2)进行性能对比,探讨了改性熟石灰用于古建筑修复的合理性.结果表明:由于火山灰反应及对熟石灰微观结构的影响,矿渣、CFBC脱硫灰和硅灰均可明显改善熟石灰的力学性能、防水性和耐候性;与NHL2相比,掺矿渣的熟石灰力学性能、防水性、耐候性和柔性均有所提高,掺CFBC脱硫灰的熟石灰性能优势较小,掺硅灰的熟石灰抗压强度和耐候性能较好,但防水性和柔性较差.在古建筑修复中,可利用质量分数为20%的矿渣作为熟石灰的添加剂.

Properties Optimization of Hydrated Lime Used in Ancient Building Restoration and Its Mechanism

The influence of slag, circulating fluidized bed combustion(CFBC) desulfurization ash and silica fume on hydrated lime were observed to explore the feasibility of modified lime in the restoration of ancient buildings and its mechanism. Results indicate that the mechanical properties, water resistance and weather durability of hydrated lime are significantly improved by slag, CFBC desulfurization ash and silica fume, due to their pozzolanic reaction and improvement of microstructure. Compared with natural hydraulic lime(NHL2), hydrated lime with slag has higher mechanical properties, water resistance, weather durability and flexibility; the performance advantage of hydrated lime with CFBC desulfurization ash is smaller; it has higher compressive strength and weather durability, weaker water resistance and flexibility while it mixed with silica fume. In the restoration of ancient buildings, 20%(by mass)slag should be used as the admixture of hydrated lime.